Feels Like Temperature Calculator
Heat index and wind chill combined.
What would you like to do next?
Find the real feel of the weather
The thermometer only tells half the story. On a hot day, humidity stops sweat evaporating and the air feels hotter than it is; on a cold day, wind strips warmth from your skin and it feels colder. This calculator combines both effects into a single feels-like figure, automatically applying the official heat index formula when it is warm and humid and the wind chill formula when it is cold and windy, exactly as weather services do. Enter the temperature, the humidity and the wind speed in either Celsius with km/h or Fahrenheit with mph, and it shows the apparent temperature, which model it used and how many degrees warmer or colder it feels. It is useful for planning a run, dressing for the cold or judging a heat warning, and it all runs in your browser.
When each effect applies
Heat index needs warm air, roughly 27C and above, with meaningful humidity; wind chill needs cold air, around 10C or below, with a noticeable wind. In mild conditions the feel is close to the actual reading.
Frequently asked questions
What is the difference between heat index and wind chill?
Heat index is how much hotter humidity makes warm air feel, while wind chill is how much colder wind makes cold air feel. The calculator picks the right one for the conditions.
Why does humidity make heat feel worse?
Your body cools by evaporating sweat. When the air is already humid, sweat evaporates slowly, so you shed less heat and the temperature feels higher.
Which units can I use?
Either Celsius with wind in km/h, or Fahrenheit with wind in mph. The result is shown in whichever temperature unit you choose.